BIOLOGY

MISTAKES VCE EXAMS

what is an operon

a functional unit of DNA found in prokaryotes, that contains a cluster of genes with related functions controlled by promoter and operator. found in prokarytic organsims.

PAM sequence

• protospacer adjacent motif is a short, specific DNA sequence that is essential for CRISPR CAS 9 to bind to and cut DNA => it is found adjacent to target sequence. it plays a crucial role in the function of Crispr cas 9 systems .The PAM sequence is recognized by the Cas9 protein and helps ensure specificity in target DNA editing during the CRISPR process.

DESCRIBE AN ORGANISMS PROTEOME AND HOW DO ORGANISMS ACHIEVE SUCH DIVERSITY IN CELLS

• The proteome is all possible proteins that could make up an organism.

• Despite having the same genetic code, the cells in the body are able to differentiate, produce different proteins, functions and structures due to gene regulation. Gene regulation is the process where the body is able to switch off and TURN ON the synthesis of specific structural genes, causing different proteins to be formed as a result.

• This may lead to different structures, shapes and functions depending on what the cell is needed for in the body.

• The intestinal epithelial cell lines the digestive tract, and is needed for the uptake of nutrients. In order to fulfill this function, the epithelial cell membrane is folded, to increase surface area to volume ratio.

• In the Fat cell, there is a large vacuole that is able to store fat. 

How do enzymes play an important role in metabolic pathways

• enzymes increase average energy of reactant molecules. 

Adding oxygen could enable yeast cells to produce more ethanol and consume more glucose, is this right?

•  Adding oxygen will lead to overall less ethanol being produced. Despite anaerobic fermentation still being evident in the presence of oxygen, it is likely that aerobic respiration will also occur, which leads to production of carbon dioxide, but not ethanol. Therefore the presence of oxygen, will decrease overall ethanol yield 

CRISPR CAS 9 for agriculture

• altering rubisco gene

• more chloroplast concentration allowing for more absorbtion of light

PCR stages

• denaturation 95 degrees breaks hydrogen bonds between DNA d=strands

• annealing 50-55 degrees. optimal temperature for forward and reverse primers to be added to each strand

• elongation 72 degrees- allow for taq polymerase found in hotter environments to work optimally, adding nucleotides

Natural killer cell (NKT)

part of the inate immune system. recognises foreign virus and release enzymes from granules to kill it

or release cytokines to alert macrophages

the cell recognises foreign antigens on MHC class I markers of virus and takes non specific steps to kill it (apoptosis)

Limitations to fossil record 

• fossil record is incomplete eg not every fossil has been found. Fossils in between could be missing offering crucial information

• parts of fossils are found, doesn’t give complete picture

• scientists will have different ideas, making it inconsistant and not concrete evidence 

can a vaccine be produced for thunder storm asthma (allergens) 

• a vaccine cannot be produced for allergens 

• multiple allergens are responsible in the fragments of pollen

• when you creat a vaccine you stimulate immune repsonse, but a sever immune response has already occured

• production of vaccine will mean that: more antibodies are produced stimulating a larger immune response 

cell and protein involved in allerigic reaction

• mast cells- release histomine to initiate inflamatory response

• histomine leads to vasodilation of blood vessels, and permeability of vessels allowing immune cells such as macrophages engluf pathogens/allergens

• IgE antibodies is the protein involved

how to reduce risk of developing sever allergies or thunderstorm asthma

• antihistimines - to calm down immune response, mast cells releasing histomines

• wear a mask to prevent allergens (airborne) to enter nose or mouth, and into system

name 2 inputs of photosynthesis that would need to diffuse from the cytosol of the plant cell across the chloroplast membranes and into chloroplast?

water and carbon

role of co enzymes NADPH and ATP

• NADPH - electron and proton carrier (H+) which loads and unloads

• ATP releases energy

a section of an RNA molecule found in the nucleus of the cell associated with the translationof these 10 amino acidswas found to contain over 300 monomers.

explain why there are over 300 monomers in this section of RNA molecule but only 10 amino acids are translated?

• due to introns (non coding regions) that do not code for amino acids. these are cut out in the rna processing stage

• 3 nucleotides make up one codon, there are 10 codons, and 30 nucleotides in 10 amino acids

Aneuploidy

abnormal nuber of chromosomes